title: Effect of physical activity on weight loss, energy expenditure, and energy intake during diet induced weight loss.
abstract: OBJECTIVE
  Objective measurements of physical activity (PA), energy expenditure (EE) and energy intake can provide valuable information regarding appropriate strategies for successful sustained weight loss.
  
  
  METHODS
  The total EE was examined by doubly labeled water, resting metabolic rate by indirect calorimetry, PA with activity monitors, and energy intake by the intake/balance technique in 116 severely obese undergoing intervention with diet alone (DO) or diet plus PA (D-PA).
  
  
  RESULTS
  Weight loss of 9.6 ± 6.8 kg resulted in decreased EE which was not minimized in the D-PA group. Comparing the highest and lowest quartiles of increase in PA revealed a lower decrease in TDEE (-122 ± 319 vs. -376 ± 305 kcal day⁻¹), elimination of the drop in AEE (83 ± 279 vs. -211 ± 284 kcal day⁻¹) and greater weight loss (13.0 ± 7.0 vs. 8.1 ± 6.3 kg). Increased PA was associated with greater adherence to energy restriction and maintenance of greater weight loss during months 7-12.
  
  
  CONCLUSIONS
  Noncompliance to prescribed PA in the DO and D-PA groups partially masked the effects of PA to increase weight loss and to minimize the reduced EE. Increased PA was also associated with improved adherence to prescribed caloric restriction. A strong recommendation needs to be made to improve interventions that promote PA within the context of behavioral weight loss interventions.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Medicine, School of Medicine, Pittsburgh, Pennsylvania.
authors.forename: James P
authors.initials: JP
authors.lastname: DeLany
authors.forename: David E
authors.initials: DE
authors.lastname: Kelley
authors.forename: Kazanna C
authors.initials: KC
authors.lastname: Hames
authors.forename: John M
authors.initials: JM
authors.lastname: Jakicic
authors.forename: Bret H
authors.initials: BH
authors.lastname: Goodpaster
mesh_terms: D050154:Adiposity; D000328:Adult; D001521:Behavior Therapy; D015992:Body Mass Index; D003131:Combined Modality Therapy; D004038:Diet, Reducing; D002149:Energy Intake; D004734:Energy Metabolism; D005234:Fatty Liver / Q000209:etiology / Q000517:prevention & control; D005260:Female; D006801:Humans; D050152:Intra-Abdominal Fat / Q000473:pathology; D008099:Liver / Q000473:pathology; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory; D009043:Motor Activity; D009767:Obesity, Morbid / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D010349:Patient Compliance; D010414:Pennsylvania; D016138:Walking; D015431:Weight Loss